How to upgrade the software called Everything published by Void Tools?
The reason that was given is "details or clarity," which clearly isn't the issue.
There are a couple of answers and comments that overlap, so I'll answer here.
"Clean installation" was a poor choice of words since it also has a technical meaning. The rest of the paragraph explains what I meant: no unnecessary traces are left.
My question was simple. So simple that adding info just complicated it. Adding reasoning for people who thought it was trivial turned the whole thing to something philosophical.
Anyway, I cleaned the question and posted a full detailed answer.